The invention concerns a low density semifinished product for manufacturing buoyant products, comprising a plurality of layers of closed-cell expanded material, having a specific gravity lower than that of water, the said layers being flexible and elastic and being joined together by means of consecutive quilting spaced so as to define pockets of air between them to increase buoyancy.
Such a semifinished product, classified in the category of xe2x80x9cnon-woven fabricxe2x80x9d, is employed mainly for manufacturing items of clothing, such as jackets, overalls, items of clothing for specific uses, for fishing, sailing, or other activities, particularly for use in marine or aquatic environments in general, and for manufacturing objects aiding in natatorial activities, as well as bags, or holders in general for use in proximity to these environments and which require protection against the risk of sinking.
Conventional items of clothing that enable a person to remain afloat are most uncomfortable and do not allow the degree of agility of movement that would be preferable when carrying out working activities, or sporting activities, or other types of activities.
Furthermore, when manufacturing buoyant products in general, to obtain holders, covers, bags, or other items, a limitation has been found consisting of the fact that it is necessary to adopt special manufacturing processes which entail considerable costs. Also, the products obtained with these processes turn out to be rigid and difficult to handle.
Examples of products having buoyant characteristics are available from the documents U.S. Pat. No. 5,267,519, FR-A-2.724.569 and, in particular, from WO-A-9422712, the last one teaching a product based on a plurality of superimposed layers.
Such prior art may be subject to further improvements with a view to eliminating the said drawbacks.
From the foregoing emerges the need to solve the technical problem of inventing a semifinished product that is suitable for manufacturing, in an extremely simple manner, buoyant products or that assist buoyancy, such as items of clothing, that are soft and easy to handle; in the case of clothing, these have to offer an adequate degree of buoyancy without excessively limiting freedom of movement.
The invention solves the said technical problem by adopting a semifinished product of the type mentioned in the preamble characterised in that the quilting is preferably arranged in closed patterns.
This considerably improves the buoyancy in water of objects made with the semifinished product, in that it creates a series of pockets in which air isxe2x80x94so sayxe2x80x94trapped, providing a more stable and long-lasting aid to buoyancy.
The closed patterns may also be obtained with cross quilting; in this case, the items of clothing manufactured with such a semifinished product have an improved wearability and are more comfortable.
The cross quilting also confers a particular resistance to mechanical stresses to the semifinished product, especially during processing, in that it keeps the layers securely joined together.
As a result of this invention it is possible to manufacture buoyant products of pleasant appearance, substantially without imposing limitations on the creative impulse of fashion designers, in that the semifinished product may substantially be processed like a fabric and may be inserted in any type of item of clothing, or accessory, without compromising the look and/or the practicality of said item.